The present invention relates generally to electronic devices having a cover assembly that is pivotable between an open position and a closed position and, more particularly, to a flip cover sensor unit for a cellular phone that senses opening or closing of the flip cover.
Many portable cellular phone designs include a cover member that covers the key pad and/or other features of the phone when not in use. Known cover members include those that are hinged to the phone housing and those that slide over the phone housing. The cover member (often called a "flip") protects its covered features from contaminants such as dirt and the like.
In operation, it is advantageous for the phone to automatically enter an "off-hook" condition or return to an "on-hook" condition when the flip cover is open or closed, respectively. The operation of opening or closing the flip should serve as an indication that the user wants to initiate or answer a call when opening the flip cover or terminate a call when closing the flip cover. It is thus necessary to provide a mechanism to alert the phone that the flip cover is either opening or closing, without requiring the user to perform a second operation, such as pushing a power button or switch.
It has been known to provide a sensing mechanism that senses flip cover opening and closing. Typically, these mechanisms include a magnet in the cover member and a Reed switch or Hall effect switch in the main terminal body. Displacement of the cover member by a user activates the switch to produce a phone off-hook condition. A user can thus answer an incoming call simply by displacing the cover member without having to perform any additional steps. These switches, however, are typically quite expensive and have limited life spans. In addition, the switches are particularly sensitive to shock loads.